Study sheds light on rare subcutaneous panniculitis-like T-cell lymphoma

A recent comparative analysis shed light on the differences between subcutaneous panniculitis-like T-cell lymphoma and the similar adipotropic lymphoproliferative disorder, according to a study.

Joan Guitart, MD, of the department of dermatology and pathology at Northwestern University, and colleagues suggested that knowledge gaps exist surrounding subcutaneous panniculitis-like T-cell lymphoma (SPTCL), largely due to the rarity of the condition, diagnostic difficulties and a dearth of case studies.

“Our research on an extremely rare cutaneous lymphoma was possible by gathering data from six of the largest academic centers dedicated to [cutaneous lymphomas],” Guitart told Healio.

All cases in the retrospective review were evaluated by groups of pathologists, dermatologists and oncologists with expertise in this area. Eligible cases were diagnosed between 1998 and 2018.

Overall, the 95 included cases were determined to be SPTCL (n = 75) or adipotropic lymphoproliferative disorder (ALPD; n = 20). The median age of the group was 38 years (range, 2-81 years). The female-to-male ratio was 2:7.

Results showed a similar clinical presentation for both groups in terms of tender nodules. Multiple tender nodules were found in 61 of 72 cases (85%), whereas single tender nodules were observed in 11 of 72 cases (15%). Most of these were in the extremities and occasionally resulted in lipoatrophy.

However, only patients with SPTCL demonstrated hemophagocytic lymphohistiocytosis (HLH).

Complete remission was achieved by 67% of 90 patients over a mean follow-up duration of 56 months.

Remission was achieved using a median of three cumulative therapies (range, 1-7).

While relapse was common, there were no fatalities or progression to HLH.

Progression from ALPD to SPTCL was reported in two patients who did not have associated systemic symptoms or HLH, according to the findings.

“Our experience shows that SPTCL does not behave like other lymphomas,” Guitart said. “Unlike other malignancies, SPTCL morbidity and mortality is purely related to hemophagocytic syndrome — a cytokine storm — rather than metastatic progression, which was not observed in any of the cases.”

But this is not the only conclusion Guitart and colleagues drew.

“Our study also emphasizes that the initial presentation is difficult to diagnose for the pathologist, since it overlaps with more indolent conditions like lupus panniculitis,” Guitart said.